• Paul Burton's avatar
    irqchip/mips-gic: Match IPI IRQ domain by bus token only · 547aefc4
    Paul Burton authored
    Commit fbde2d7d ("MIPS: Add generic SMP IPI support") introduced
    code which calls irq_find_matching_host with a NULL node parameter in
    order to discover IPI IRQ domains which are not associated with the DT
    root node's interrupt parent. This suggests that implementations of IPI
    IRQ domains should effectively ignore the node parameter if it is NULL
    and search purely based upon the bus token. Commit 2af70a96
    ("irqchip/mips-gic: Add a IPI hierarchy domain") did not do this when
    implementing the GIC IPI IRQ domain, and on MIPS Boston boards this
    leads to no IPI domain being discovered and a NULL pointer dereference
    when attempting to send an IPI:
    
      CPU 0 Unable to handle kernel paging request at virtual address 0000000000000040, epc == ffffffff8016e70c, ra == ffffffff8010ff5c
      Oops[#1]:
      CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.7.0-rc6-00223-gad0d1b6 #945
      task: a8000000ff066fc0 ti: a8000000ff068000 task.ti: a8000000ff068000
      $ 0   : 0000000000000000 0000000000000001 ffffffff80730000 0000000000000003
      $ 4   : 0000000000000000 ffffffff8057e5b0 a800000001e3ee00 0000000000000000
      $ 8   : 0000000000000000 0000000000000023 0000000000000001 0000000000000001
      $12   : 0000000000000000 ffffffff803323d0 0000000000000000 0000000000000000
      $16   : 0000000000000000 0000000000000000 0000000000000001 ffffffff801108fc
      $20   : 0000000000000000 ffffffff8057e5b0 0000000000000001 0000000000000000
      $24   : 0000000000000000 ffffffff8012de28
      $28   : a8000000ff068000 a8000000ff06fbc0 0000000000000000 ffffffff8010ff5c
      Hi    : ffffffff8014c174
      Lo    : a800000001e1e140
      epc   : ffffffff8016e70c __ipi_send_mask+0x24/0x11c
      ra    : ffffffff8010ff5c mips_smp_send_ipi_mask+0x68/0x178
      Status: 140084e2        KX SX UX KERNEL EXL
      Cause : 00800008 (ExcCode 02)
      BadVA : 0000000000000040
      PrId  : 0001a920 (MIPS I6400)
      Process swapper/0 (pid: 1, threadinfo=a8000000ff068000, task=a8000000ff066fc0, tls=0000000000000000)
      Stack : 0000000000000000 0000000000000000 0000000000000001 ffffffff801108fc
                0000000000000000 ffffffff8057e5b0 0000000000000001 ffffffff8010ff5c
                0000000000000001 0000000000000020 0000000000000000 0000000000000000
                0000000000000000 ffffffff801108fc 0000000000000000 0000000000000001
                0000000000000001 0000000000000000 0000000000000000 ffffffff801865e8
                a8000000ff0c7500 a8000000ff06fc90 0000000000000001 0000000000000002
                ffffffff801108fc ffffffff801868b8 0000000000000000 ffffffff801108fc
                0000000000000000 0000000000000003 ffffffff8068c700 0000000000000001
                ffffffff80730000 0000000000000001 a8000000ff00a290 ffffffff80110c50
                0000000000000003 a800000001e48308 0000000000000003 0000000000000008
                ...
      Call Trace:
      [<ffffffff8016e70c>] __ipi_send_mask+0x24/0x11c
      [<ffffffff8010ff5c>] mips_smp_send_ipi_mask+0x68/0x178
      [<ffffffff801865e8>] generic_exec_single+0x150/0x170
      [<ffffffff801868b8>] smp_call_function_single+0x108/0x160
      [<ffffffff80110c50>] cps_boot_secondary+0x328/0x394
      [<ffffffff80110534>] __cpu_up+0x38/0x90
      [<ffffffff8012de4c>] bringup_cpu+0x24/0xac
      [<ffffffff8012df40>] cpuhp_up_callbacks+0x58/0xdc
      [<ffffffff8012e648>] cpu_up+0x118/0x18c
      [<ffffffff806dc158>] smp_init+0xbc/0xe8
      [<ffffffff806d4c18>] kernel_init_freeable+0xa0/0x228
      [<ffffffff8056c908>] kernel_init+0x10/0xf0
      [<ffffffff80105098>] ret_from_kernel_thread+0x14/0x1c
    
    Fix this by allowing the GIC IPI IRQ domain to match purely based upon
    the bus token if the node provided is NULL.
    
    Fixes: 2af70a96 ("irqchip/mips-gic: Add a IPI hierarchy domain")
    Signed-off-by: default avatarPaul Burton <paul.burton@imgtec.com>
    Cc: linux-mips@linux-mips.org
    Cc: Jason Cooper <jason@lakedaemon.net>
    Cc: Qais Yousef <qsyousef@gmail.com>
    Cc: Ralf Baechle <ralf@linux-mips.org>
    Cc: Marc Zyngier <marc.zyngier@arm.com>
    Cc: stable@vger.kernel.org
    Link: http://lkml.kernel.org/r/20160705132600.27730-2-paul.burton@imgtec.comSigned-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
    547aefc4
irq-mips-gic.c 27.8 KB